Data Over Cable Service Interface Specifications (DOCSIS) are developed by CableLabs, a non-profit consortium of cable operators focused on technologies and specifications for delivery of data signals that carry information such as data, video, voice, or other information, and for delivery of additional next generation services. DOCSIS defines the signal parameters for communications transmissions over a cable service infrastructure.
Evolution in the cable industry, particularly in the cable television service, has resulted in the reduction or elimination of traditional analog television channels that previously utilized frequencies as low as 54 MHz in the United States. This has freed spectrum within the cable system infrastructure, and the progression of DOCSIS specifications has begun to incorporate more of this spectrum. DOCSIS 3.1, for example, specifies an upstream frequency range of 5 MHz up to 204 MHz, which is almost 2.5 times the frequency range supported by DOCSIS 3.0, covering more than five and a third octaves. Additionally, full compliance with DOCSIS 3.1 requires support for power output up to 65 dBmV into 75 Ohm loads across the entire spectrum. Conventional amplifiers for these systems have not met the demanding challenges of power output dynamic range across the wide spectrum range necessary for full compliance with DOCSIS 3.1 and anticipated future standards.